Dog's curse

[stevenmai]

All right, this one contains bad language, and was thought up while me and my friend were chitchatting last night, so here we go.
Two dogs are arguing, one of them yells at the other one : You son of a bXX!
The other one does not seem upset or angry, just frowns and asks with curiosity : You...you aren't ?
So that's the end of the joke, not sure if you guys feel funny, but it is to me. ^^